For industrial vehicles, e.g. forklift car, solid tires are widely used. A pneumatic-shaped solid tire is one of such solid tires. The pneumatic-shaped solid tire has a similar profile to a usual pneumatic tire and is mounted on a rim which is originally for the same size pneumatic tire.
For example, in each of Japanese patent publications JP-A-61-44005 and JP-A-64-83405, such a pneumatic-shaped solid tire is disclosed, wherein a tire main body is composed of three rubber layers, a radially innermost base rubber layer, a radially outermost tread rubber layer and an in-between cushion rubber layer. The base rubber layer is made of a rubber compound reinforced by short organic fiber cords mixed therewith in order to greatly increase the compressive elastic modulus or rigidity, which intends to improve the engaging force between the tire and rim. Further, the rigid base rubber layer extends over the radially outer edge of the rim flange, and a reinforcing cord layer is disposed at such a higher position being radially outward of the above-mentioned outer edge of the rim flange. Therefore, a great engaging force is obtained in the initial stage of the tire life.
However, when the base rubber layer is aged, the friction between the base rubber layer and the rim is reduced, and the rubber volume is slightly decreased. Accordingly, the engaging force is decreased. As a result, a slippage occurs between the tire and rim.
Even if it is assumed that the reinforcing cord layer produces a hooping force, the force can not reach to the rim because a rigid compressive resistant rubber layer exists therebetween. Accordingly, such a reinforcing cord layer can not prevent the rim slip.
Further, as the reinforcing cord layer is disposed near or at the boundary between the rigid base rubber layer and the relatively soft in-between cushion rubber layer, a separation failure of the cushion rubber was sometimes observed.